The Tacit Is Hand-Mounted Sonar For The Vision Impaired

Every once in a while you see an invention that seems a long time coming.

The Tacit, a hand-mounted system that pings surroundings and transmits distance information to the user, is one of those. While the reliable white cane and occasional accommodations for the blind and vision impaired ameliorate the difficulty of navigating the world sans sight, technological advances that are both useful and ready for deployment are few and far between.

The system uses two ultrasonic sensors that can detect the distance of objects between 2cm and 3m away. Mounted facing off to the right and left, they can be swept across a room and will be able to sense most common obstacles and dangerous objects. They send their signal through an Arduino Mini controller, which governs a pair of servos. These servos each press a loop of foam down on the wrist: the closer the object, the harder they press. The whole thing is powered by a 9V battery and straps onto either hand.

Designs like this are the reason we have a patent system. And while tech companies are filing thousands of patents for trivial UI items and software methods, the inventor, Steve Hoefer, has opted instead to give away his invention for free under a Creative Commons license. As is increasingly common with interesting hacked inventions like this, he has published the parts list, detailed instructions, a circuit diagram, and the source code for the Arduino controller.